Background: The few studies that examine the effect of nasal abnormalities on continuous positive airway pressure device (CPAP) adherence are controversial. The aim of this study was to evaluate the contribution of nasal abnormalities in CPAP adherence.
Methods: We included patients with moderate to severe OSA. The patients were submitted to rhinoscopy, nasofibroscopy, nasal inspiratory peak flow, and acoustic rhinometry. The patients who used a CPAP for 4 h or more per night for at least 70 % of the nights over a 6-month period were considered to have good adherence.
Results: Thirty-four patients finished the study. Eleven (33.4 %) were female and 23 (67.6 %) were male. Sixteen (47.1 %) patients had good adherence. The body mass index (p = 0.030), neck circumference (p = 0.006), and apnea-hypopnea index (p = 0.032) were higher, and the oxyhemoglobin saturation minimum was lower (p = 0.041) in the good adherence group. Nasal parameters showed no differences between good and poor adherence groups. In Spearman's correlation, surprisingly, there was a negative correlation between the highest number of hours of CPAP use with smaller values of nasal minimal cross-sectional areas in the supine position (r, 0.375; p = 0.029). In the linear regression model, the nasal findings that predicted increased of the CPAP use were the following: lower scores of nasal symptoms (p = 0.007) and lower nasal volume in supine position (p = 0.001).
Conclusions: The majority of the nasal parameters evaluated in this study did not influence CPAP adherence.